In this article, we investigate the effects of the app "Fingu" on a child's understanding of the part-whole concept. Using the Artifact Centric Activity Theory framework, we initially analyse the internalisation and externalisation processes that appear to occur during one child's use of the app. Based on the learning from this process,…

Digital multi-representation applets offer promising opportunities for promoting students' conceptual understanding by dynamically converting graphical and symbolic representations and for promoting discoveries and justifications of mathematical properties. However, learning effects of open-ended multi-representation applets seem to depend on…